Vacuum cleaner with flexible rotary-pistons



1961 HIROSHI FUKUBA 2,994,098

VACUUM CLEANER WITH FLEXIBLE ROTARY-PISTONS Filed Jan. 23, 1957 3Sheets-Sheet 1 FUJ' INVENTOR. /'///?0H/ FUKUBA Aug. 1951 HIROSHI FUKUBA2,994,098

VACUUM CLEANER WITH FLEXIBLE ROTARY-PISTONS Filed Jan. 23. 1957 3Sheets-Sheet 2 INVENTOR. #09051 FURL/8A ATTORNEY 1961 HlROSHl FUKUBA2,994,098

VACUUM CLEANER WITH FLEXIBLE ROTARY-PISTONS Filed Jan. 25, 1957 3Sheets-Sheet 5 IN VEN TOR. HMPOJH/ FuKl/BA The present invention relatesto a motorless, handmoved vacuum cleaner which is operated by means offlexible rotary-pistons that rotate by prime mover-wheels revolving onthe floor through friction. This invention is characterized in that afew pieces of fabric which act as rotary-pistons, are carried on a shaftequally spaced, and the free end of these fabric pieces are held inclose contact with the curvature of a cylinder wall through centrifugalforce. Dust is drawn in from the front, and then compressed with airinto the dust chamber through the sudden stretching of bent fabrics.

The object of this invention is to provide contacting action of thefabric pieces which are in contact with the inside-wall of the enclosurewhile rotating.

The attached drawings show one embodiment of the invention;

FIG. 1 is a perspective view of the vacuum cleaner;

FIG. 2 is an enlarged view from below;

FIG. 3 is a plan view with the handle removed;

FIG. 4 is a section taken on the line 44 of FIGS. 2 and 3;

FIG. 5 is a section taken on the line 55 of FIGS. 2 and 3; and

FIG. 6 is a perspective view of flexible flaps carried on their shaftwhich is removed from the case.

As shown in FIG. 1 and FIG. 3, a case 11 and its upper wall 8 are madeof a material such as metal. A fluted guide roller 18, made of softrubber, is carried on front of the case 11. A trailing wheel 9 iscarried in a recess on the rear end of a bottom cover 10. The cleaner asa whole, can be moved on the floor by means of the guide roller 18 andthe trailing wheel 9 when force is applied to the handle.

Two friction wheels 7, 7 are carried on each side of the case 11 asshown in FIG. 2 and FIG. 5. These wheels are driven by contact with thefloor and act as a prime mover. Friction rollers 3, 3 fitted on bothends of shaft 2 of the rotary piston, are closely in contact withfriction wheels 7, 7, and as the rollers 3, 3 are smaller than thewheels 7, 7 in diameter the shaft 2 acquires a fast rotating speed. Theend of shaft 2 is fitted into its bearing slot with sufiicient force tomaintain it in vertical position, but to permit rotation of said shaft.

A few pieces of flexible materials such as fabric flaps 1, 1, 1", 1" areattached to this shaft 2 with equal pitch on its profile-circle as shownin FIG. 6. The number of fabric flaps acting as rotary pistons may befour or more.

The free ends of the fabric flaps tend to stretch outward due tocentrifugal force when the shaft rotates. In order to make this tendencymore effective, the end parts of the flaps may be folded back and sewedtogether as shown in FIG. 6.

The inside curvature of the case 8 forms a part of a cylinder, andprovides a front-wall 4 and a back-wall 5 which are both circularlycurved.

The fabric flaps 1 1" are made so long that they cannot fully stretchinside the case as they are restricted by surrounding walls 4 and 8during their rotating motion, but the end port of each flap followsalong front-wall 4, upper-wall 8 and back-wall 5 with its free end bentbackward. Therefore, the spaces surrounded by the flaps 1 1", front-wall4 and upper-wall 8 are kept air tight which results in drawing in thedust when the flap comes to position 1' in FIG. 4. When the flapadvances Patented Aug. 1, 1961 lee to inlet 5' of dust chamber 6, thebent partof flap 1'' is stretched out as its end comes free, and dust isreleased when flap 1" strikes against the upper edge of the backwall 5,and is forced into the dust chamber by the air propelled by thefollowing flap.

A door 8 is hinged to the case 8 which opens while the compressionprocess is going on, as shown in FIG. 4. This door 8' acts as the checkvalve to prevent air from flowing from the dust collector bag toward thesuction chamber either between successive flap positions or when theflaps remain stationary. The free end of the flap which has passed theinlet space 5' is bent back again by the back wall as shown at 1" inFIG. 4.

The flaps act to gather dust at the front of the case by their lappingmotion between the positions indicated at 1 to 1. Each flap 1 1" in turnrepeats the process described above.

A dust bag 16 made of fabric, connected to an operat ing handle 15 witha tension spring 17, is attached just over dust inlet 12 which is out onthe back-wall of the case 8. The operating handle 15 is provided with abifurcated member 13 pivoted on the case 8 at 14. The dust bag expandswhen dust is forced into it with air, but the air soon escapes throughthe fabric and the dust falls into dust chamber 6.

The cleaner is moved forward and backward on floors by handle 15, butthe actual dust-drawing operation is done in the forward motion only. Toavoid reverse motion of the flaps during the backward motion, bearingsfor the prime mover-wheels 7, 7 are shaped in the form of elongatedslots 22 as shown in FIGS. 4 and 5, so as to cut the friction contactwith the rollers 3, 3 of the rotating shaft 2.

To clean the dust chamber 6, a bottom plate 10 pivoted at 20 may beopened by pushing a catch 21. Small brushes 19, 19 are fitted at bothends of the front of the casing to sweep dust from corners. Instead offriction wheels 7, 7 in the said embodiment, an electric motor as aprime mover may be used to drive the shaft. Although but one embodimentof the invention has been illustrated and described in detail, it is tobe expressly understood that the invention is not limited thereto.Various changes can be made in the design, arrangement, and constituentsof the parts Without departing from the spirit and scope of theinvention, as the same will now be understood by those skilled in theart.

What I claim is:

l. A vacuum cleaner movable over a floor, comprising a housing forming agenerally cylindrical chamber having a horizontal axis, said housinghaving a curved peripheral wall and having a dust intake opening at thebottom of said chamber registering with said floor and a dust dischargeopening at an elevation above said intake opening, a horizontal shaftdisposed axially in said chamber, means, including a plurality ofwheels, for driving said shaft, said wheels being adapted to supportsaid vacuum cleaner, a plurality of flaps of impervious flexiblematerial mounted on said shaft, said flaps having a flexibility suchthat they do not engage said peripheral wall when at rest and beingadapted to be extended centrifugally due to the rotation of said shaftto engage and form an air seal with said peripheral wall, whereby saidflaps act as pistons to draw air and dust from said floor through saidintake opening and to discharge said air and dust through said dischargeopening, and a projection in said housing positioned in the path of therotating flaps whereby said flaps during the rotation thereof come intocontact with said projection with appreciable force.

2. A vacuum cleaner movable over a floor, comprising a housing forming agenerally cylindrical chamber having a horizontal axis, said housinghaving a curved peripheral wall and having a dust intake opening at thebottom of said chamber registering with said floor and a dust dischargeopening at an elevation above said intake opening, a horizontal shaftdisposed axially in said chamber, means, including a plurality ofwheels, for driving said shaft, said wheels being adapted to supportsaid vacuum cleaner, a plurality of flaps of impervious flexiblematerial mounted on said shaft, said flaps having a flexibility suchthat they do not engage said peripheral Wall when at rest and beingadapted to be extended centrifugally due to the rotation of said shaftto engage and form an air seal with said peripheral Wall, whereby saidflaps act as pistons to draw air and dust from said floor through saidintake opening and to discharge said air and dust through said dischargeopening and a check valve disposed in said discharge opening and adaptedto prevent the reverse flow of air through said opening, and aprojection in said housing positioned in the path of the rotating flapswhereby said flaps during the rotation thereof come into contact withsaid projection with a force of such degree to cause the opening of thecheck valve.

3. A vacuum cleaner as set forth in claim 1 having the wheels disposedto engage and be driven by movement of said cleaner over said floor andmeans connecting said wheels to drive said shaft.

4. A vacuum cleaner as set forth in claim 3 having a one-way couplingmechanism to interrupt the drive of said shaft when said wheels rotatein a reverse direction as the cleaner is moved to and fro over a floor.

5. A vacuum cleaner as set forth in claim 1 in which said fiaps areprovided at their ends with portions adapted to be folded over due toengagement with said walls.

References Cited in the file of this patent UNITED STATES PATENTS 22,488Carey Jan. 4, 1859 112,837 Norris Mar. 21, 1871 479,616 Bennett July 26,1892 541,992 Cloud et al. July 2, 1895 609,145 Harvey Aug. 16, 1898642,172 Sweitzer Ian. 30, 1900 643,386 Smith Feb. 13, 1900 1,224,349Yessne May 1, 1917 1,426,954 Brooks Aug. 22, 1922 1,558,006 Fisker Oct.20, 1925 1,594,685 Osius Aug. 3, 1926 1,915,073 Svensson June 20, 19332,348,861 Smellie May 16, 1944 2,537,523 Frost Ian. 9, 1951 2,722,709Yerkes Nov. 8, 1955 FOREIGN PATENTS 4,931 Great Britain 1878 449,913Great Britain July 7, 1836

